1. Field of the Invention
The present invention relates generally to a multi-functional mobile terminal with a mobile phone function, and more particularly to a multi-functional mobile terminal for incorporating a mobile phone module and a PDA (Personal Digital Assistant) module for storing information and searching for information on Internet in one manufactured product. The mobile phone module and the PDA module are provided with individual power-supply voltages, respectively, and thereby operate independently of each other.
2. Description of the Related Art
Typically, a PDA (Personal Digital Assistant) is a general term for palm-sized devices for personal and business use, mainly used to perform calculation, searching for or storing of necessary information therein. Also, the PDA has been widely used to manage schedule, calendar, and address book information. Such a PDA has been called a kind of pocket-sized computer, for example, Palmtop manufactured by HP (Hewlett-Packard) Company, and Palmpilot manufactured by 3Com Corporation.
Most PDAs contain a small-sized keyboard for receiving commands from users. However, some PDAs may contain an electromagnetic pad for sensing commands written by a prescribed character entry means such as a user's body and a touch pen. The PDA has been widely used to store/search for schedule and address book information, and enable a user to enter a desired memorandum therein. Recently, with the increasing development of many application programs for such a PDA, a multi-functional mobile terminal for incorporating a mobile phone module and a pager module in one body is now being produced on a commercial scale.
FIG. 1 is a view illustrating a block diagram of a conventional multi-functional mobile terminal incorporated with a mobile phone module and a PDA module in one body. Referring to FIG. 1, a conventional multi-functional mobile terminal 10 includes a mobile phone module 20 for executing a mobile phone function and a PDA module 30 for executing a PDA function.
The mobile phone module 20 includes a sub-microcomputer (Sub-MICOM) 22 for controlling overall operations of the mobile phone functions. The PDA module 30 includes a main microcomputer (Main-MICOM) 34 for controlling overall operations of the PDA functions. The PDA module 30 further includes an LCD (Liquid Crystal Display) 32 for displaying operation states of the multi-functional mobile terminal 10. A representative example of the sub-MICOM 22 is an MSM (Mobile Station Modem) manufactured by Qualcomm Company, and a representative example of the Main-MICOM 34 is the ‘Dragoon boll’ manufactured by the Palm Company. The sub-MICOM 22 and the main-MICOM 34 are interconnected over an interface 42, and thereby mutually controlled via the interface 42.
The main-MICOM 34 senses an operation status of the PDA module 30 and an operation status transmitted from the sub-MICOM 22 of the mobile phone module 20, and displays the operation statuses on the LCD 32. The multi-functional mobile terminal 10 further includes a power-supply unit 40 for selectively providing a power-supply voltage for either the mobile phone module 20 or the PDA module 30 according to the type of entry signal. Therefore, if a user only wants to use functions of the mobile phone module 20 in the multi-functional mobile terminal 10, the power-supply unit 40 provides only the mobile phone module 20 with a power-supply voltage by the use of a power-supply selection switch (not shown) mounted on the multi-functional mobile terminal 10. Otherwise, if the user only wants to use functions of the PDA module 30 in the multi-functional mobile terminal 10, the power-supply unit 40 provides only the PDA module 30 with a power-supply voltage by the use of such a power-supply selection switch (not shown).
However, the main-MICOM 34 of the PDA module 30 manages a user interface for displaying operation states of the PDA module 30 and the mobile phone module 20 and controlling other functions thereof. Therefore, the conventional multi-functional mobile terminal 10 can support the user interface by the use of the main-MICOM 34 without powering on or off the mobile phone module 20. In more detail, if the mobile phone module 20 is powered off and the PDA module 30 is powered on to activate only the PDA module 30, a variety of operation states of the PDA module 30 are displayed on the LCD 32 upon receiving a control signal from the main-MICOM 34 of the PDA module 30, in such a way that the conventional multi-functional mobile terminal is able to support the user interface. However, if the mobile phone module 20 is powered on and the PDA module 30 is powered off to active only the mobile phone module 20, the main-MICOM 34 is powered off, such that operation states of the mobile phone module 20 are not displayed on the LCD 32, resulting in an ineffective user interface.
Therefore, even when the user attempts to activate only the mobile phone module 20 without activating the PDA module 30 in the conventional multi-functional mobile terminal 10, it must power on the PDA module 30 along with the mobile phone module 20, resulting in an increase of power consumption much higher than an actually necessary power consumption level of the multi-functional mobile terminal 10.
The conventional multi-functional mobile terminal 10 allows the main-MICOM 34 of the PDA module 30 to control such a user interface. Therefore, although there occurs an error in the operations of the PDA module 30, the mobile phone module 20 under normal operation does not correctly display its own operation status on the LCD 32 because of an operation failure of the main-MICOM 34, such that the user must always reset the multi-functional mobile terminal 10 whenever there occurs an error in the operations of the PDA module 30, resulting in the increase of a user's inconvenience.